The invention relates to a terminal strip, made of insulative material, for connecting insulated wires each to a solderless, non-screwed, stripping-free terminal having a polytropic air gap, the terminal being formed of leaf-shaped resilient contact material including a slot. The main portion of the slot adjoins an enlarged insertion opening and is defined by sharp edges, the slot having a width which is smaller than the thickness of the metallic core of the wire, so that upon urging of the wire into the slot the wire insulation is severed and contact is made between the wire and the terminal. The terminal strip comprises a plurality of such terminals mounted in tandem in the longitudinal direction. For reference purposes, the terminals described above are referred to as LSA-PLUS terminals. The LSA-PLUS technique was developed by the assignee of the present invention. The terminology is derived from the German word "Lot-, Schraub- und Abisolierfrei," which means solderless, non-screwed and stripping-free, and "Polytropem Luftspalt," meaning polytrapic air gap. This is explained fully in commonly known U.S. Pat. No. 4,452,502 and the terms "LSA" and "PLUS" are employed in commonly owned U.S. Pat. No. 4,405,187.
From U.S. Pat. No. 4,283,103 a terminal strip including Z-shaped LSA-PLUS terminals has been known. The Z-shaped LSA-PLUS terminals are mounted in tandem in the longitudinal direction. These LSA-PLUS terminals comprise two upright leaf-spring arms disposed at an angle of 45.degree. which define a slot into which the respective wire is urged.
In the inserted condition of the wire the two arms of each of the leaf springs are deflected out of their original plane relative to each other (torsional effect), so that these arms sever the wire insulation at offset locations and contact the wire at a respective one of the diagonally opposite inner edges of the two arms.
On account of this torsional effect forces are transferred to the terminal strip.
In the arrangement shown in U.S. Pat. No. 4,283,103 all of the forces of the Z-shaped LSA-PLUS terminals are effective in the same direction and therefore exhibit an additive effect. Thus, a large number of wires connected to the terminal strip create a relatively large cumulative torque on the strip, tending to twist it in a clockwise or counter-clockwise direction. This can have adverse effects on the apparatus to which the strip is mounted, or on the mutual connecting or mounting means.
U-shaped LSA-PLUS terminals are shown in U.S. Pat. No. 4,171,857. From this patent it is clear that all of these terminals in the terminal strip are oriented in the same direction.